Boiler-furnace.



G. DE GRAHL.

BOILER FURNACE.

APPLICATION FILED MAR. 21, 1911.

Patented Jan. 21, 1913.

2 SHEETS-SHEET l.

FIE-1.

G. DE GRAHL.

BOILER FURNACE.

. APPLICATION FILED 111111.21, 1911.

Patented Jan. 21, 1913.

2 SHEETS-SHEET 2.

UNTTED STATES PATENT @FETfiE.

GUSTAV DE GBAI-IL, OF ZEHLENDORF, NEAR, BERLIN, GERMANY.

BOILER-FURNACE.

Application filed March 21,

To all whom it may concern:

Be it known that I, GUSTAV DE GRAHL, a subject of the German Emperor,and residing at Zehlendorf, near Berlin, Germany, have invented certainnew and useful Improvements in Boiler-Furnaces, of which the followingis a specification.

My invention relates to boiler furnaces having lateral air conduits inthe door-frame in which flap-valves adapted to open automatically underthe influence of the vacuum are pivoted. If in these boiler-furnaces oneside of the grate is highly charged with coal and in consequence thereofthe air cannot or not sufficiently pass between the grate-bars, theadditional air, which is introduced through the correspondingair-conduit cools the coal on this side of the grate, so that black orso-called dead spots are formed thereon. To meet this disadvantage, Iprovide stops above the flap-valves adjustable independently from eachother for coacting with the valves in order to limit the opening of thesame. Herewith the advantage is obtained that in fact by every one ofthe two air-conduits additional air can be admit-ted to the fire-boxunder the influence of the vacuum therein, but the maximum amount of theopening of the valves may be difierent in each air-conduit according tothe adjustment of the stops. If now at one side of the grate black ordead spots appear this stop in the corresponding air-conduit is to beadjusted in such a manner that it allows but a very small opening of thevalves. The consequence of this is, that a smaller amount of air issucked into the fire-box through the lateral air-conduit but a greateramount through the grate-bars and herewith the burning of the coal onthe grate is favored. If the stoker intends to release one side of thegrate from the slags the opening of the valves and in consequence theamount of the air entering through the corresponding lateral air-conduitis to be reduced to such an amount, as is just sufficient for coolingthe walls of the air-conduit and preventing the burning of the same,while through the air-conduit at the other side of Specification ofLetters Patent.

Fatented Jan. 21, 1913.

1911. Serial No. 615,965.

the grate which is not to be released from slags a far greater amount ofair may be introduced according to the adjustment of the stop.

One illustrative embodiment of my invention is represented by way ofexample in the accompanying drawings, wherein Figure 1 is a frontelevation of the doorframe and the fire-door, and Figs. 2 and 3 arefront elevation and horizontal section, respectively, enlarged, showingone of the two lateral air-conduits.

Referring to the drawings, the numerals 1 and 2 designate the two knownlateral air-conduits in the door-frame, in which the flap valves 3, 4are respectively arranged to rock about the pivots 5, 6, respectively.On the wall of each of the lateral air-conduits 1, 2 I attach a curvedplate 7, 8, respectively, connected by spokes 9, 10 with a sleeve 11,12, respectively. The latter are located above the valves, extendthrough the walls of the latter air-conduits 1 and 2 and each contains apivot 13, whose one end projecting into the lateral air-conduit carriesa lever 14 acting as a stop for limiting the motion of the valve andwhose other end carries a lever 15. Each lever 15 carries a handle 16containing a chamber 17. The spring 18 in the chamber 17 presses againstthe pointed head 19 on one end of the shank 20. The latter is mountedaxially displaceable in the handle and at its other end carries a nut21. Each curved plate 7 8 possesses a number of recesses or holes 22 and23, respectively, for receiving the pointed end of the head 19. Theposition of the lever 14 relatively to the valves 3, 41 is such that assoon as the heads 19 rest in the lowest of the holes 22 and 23, thelever 14 which limits the movement of the valves 3, 4 allows the valvesto be open a minimum amount which is just sufiicient for admittingsufiicient air for cooling the furnace front and preventing the burningof the same. x

According in each instance to the kind of coal which is burned and tothe size of the grate the valve can be opened a minimum amount byactuating the lever 15, whereby the furnace front is effectivelyprevented from becoming overheated.

I claim A combination with the fire-door frame, having lateralair-conduits 1, 2, flap-valves 3, 4:, adapted to open automaticallyunder the influence of the vacuum in the fire-box therein, levers 14:journaled in the Walls of 10 the conduits and adapted to stop the valveafter it has lifted itself, and means for looking' the levers 14independently from each other in various positions.

In testimony whereof, I afiix my signature in the presence of twoWitnesses.

GUSTAV DE GRAHL.

WVitnesses:

HENRY HASPER, VOLDEMAR HAUPT.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

